The present invention relates to an improvement in an optical reading apparatus for reading bar codes or the like.
An optical reading apparatus for reading bar codes for data input to an electronic cash register or the like is known. The apparatus illuminates, by, e.g., a light-emitting diode, a label on which a price or the like is printed in the form of bar codes. The difference in reflectivity due to presence/absence of bars of a code is converted to an electrical signal, thereby reading bar codes.
However, in an optical reading apparatus of this type, if the light-emitting diode is turned on constantly even when the bar codes are not read, power consumption is increased and is disadvantageous from the economical point of view. In view of this problem, it has been proposed to arrange a switch for turning on the light-emitting diode as needed. Thus, the switch is operated to turn on the light-emitting diode before starting reading operation, thereby decreasing the overall power consumption. However, this method requires incorporation of a switch and a switching operation for turning on/off the light-emitting diode for each reading operation. This resulted in cumbersome operation.